In the field of transmission of moving image data, image data is typically encoded before being transmitted over a network to a receiving computer. The encoding process is usually performed by dividing the moving image into frames, e.g., intracoded frames (I-frames) or intercoded frames (P- or B-frames), and processing each frame in a predesignated scanning order. Each encoded frame is transmitted to a receiving computer in the same predesignated scanning order, where the frame is further processed to recreate the moving image.
One method of encoding involves processing the moving image data in a raster scan order, where each frame is arranged and processed row by row. Another method involves processing the frames in a zigzag scan order, where processing begins from the top-left corner of the frame and proceeds in a zigzag pattern towards the bottom-right corner of the frame.